The present invention relates to an optical transmission system for supplying an optical signal generated by a light emitting device, and a method of manufacturing the optical transmission system.
The optical transmission system or optical coupling system of this type is configured such that an optical signal generated by a light emitting device is collected at an end portion of optical fibers via an optical lens for allowing the optical signal to be transmitted via the optical fibers. That is to say, an optical signal generated by the light emitting device is colleted by the optical lens and is supplied to the optical fibers.
The optical transmission system of this type has the following problems.
Since the optical lens must be disposed between the light emitting device and the optical fibers, it is required to ensure a space required for providing the optical lens, with a result that the number of parts becomes large, and it is difficult to miniaturize the system.
If the number of the optical fibers used is large, it is also difficult to miniaturize the optical transmission device, and is also difficult to lay out a lot of optical fibers in a desired pattern in a housing of electronic equipment. Accordingly, such a system is disadvantageous in terms of mounting.
Since heat is generated from the light emitting device upon operation, it is required to effectively transfer the heat to the outside.
An object of the present invention is to provide an optical transmission device capable of realizing the miniaturization, reducing the number of parts, and effectively performing heat radiation, and to provide a method of manufacturing the optical transmission system.
To achieve the above object, according to a first aspect of the present invention, there is provided an optical transmission system including: a light emitting device: an optical waveguide portion positioned to and disposed on the light emitting device; and a reflecting means for introducing an optical signal generated by the light emitting device to the optical waveguide portion; wherein the optical waveguide portion has a plurality of cores for transmitting the optical signal and a cladding portion for surrounding the cores; the light emitting device has a plurality of light emitting units for separately generating the optical signals; and the light emitting units are disposed in such a manner as to individually correspond to the cores.
With this configuration, since an optical signal generated by the light emitting device is reflected by the reflecting means provided on the optical waveguide portion to be introduced to the optical waveguide portion, it is possible to eliminate the need of provision of an optical lens which has been required to be provided separately from the optical waveguide portion, and hence to certainly supply the optical signal generated by the light emitting device to the optical waveguide portion.
Since the optical waveguide portion is composed of a plurality of the cores and the cladding portion for surrounding the cores, it is possible to facilitate the handling of the optical waveguide portion as compared with the conventional configuration in which a plurality of optical fibers are laid out. Since the light emitting units of the light emitting device correspond to the cores, an optical signal generated by each light emitting unit can be certainly supplied to the corresponding core via the reflecting means. Since the reflecting means is provided on the optical waveguide portion, it is possible to reduce the number of parts, and since it is required to provide an optical lens which has been conventionally used, it is possible to miniaturize the system.
In the above optical transmission system, the reflecting means is preferably disposed at an end portion of the optical waveguide portion, or at a midpoint of the optical waveguide portion.
The above optical transmission system preferably further includes a positional adjustment means for adjusting the position of the optical waveguide portion along the direction in which an optical signal is generated by the light emitting device, thereby adjusting the position of the optical waveguide portion to the light emitting device.
By use of the positional adjustment means, it is possible to accurately adjust the position of the optical waveguide portion to the light emitting device along the direction in which an optical signal is generated by the light emitting device.
In the above optical transmission system, the light emitting device is preferably directly disposed on a heat transfer portion.
With this configuration, since heat generated by the light emitting device is directly radiated to the heat transfer portion, it is possible to stably operate the light emitting device by preventing overheat of the light emitting device.
The above heat transfer portion is preferably a housing of electric equipment.
To achieve the above object, according to a second aspect of the present invention, there is provided a method of manufacturing an optical transmission system, including the steps of: disposing a light emitting device in a notch formed in a board in such a manner that the light emitting device is adjustable in its position along a first direction, and is fixed in its position along a second direction perpendicular to the first direction by the board; positioning an optical waveguide to the board; adjusting the position of the light emitting device along the first direction of the board for introducing an optical signal generated by the light emitting device to the optical waveguide portion; and fixing, after completion of the positional adjustment of the light emitting device along the first direction of the board, the light emitting device on the board side.
According to the above configuration, the notch is provided in the board, and the light emitting device is disposed in the notch. In the state in which the light emitting device is disposed in the notch, the light emitting device is adjustable in its position along the first direction and is fixed in its position along the second direction perpendicular to the first direction.
Then, the optical waveguide portion is positioned to the board, and the position of the light emitting device is adjusted along the first direction of the board for introducing an optical signal generated by the light emitting device to the optical waveguide portion. Next, after completion of the positional adjustment of the light emitting device along the first direction of the board, the light emitting device is fixed to the board.
Accordingly, it is possible to accurately perform the relative positioning of the board, optical waveguide portion, and light emitting device only by adjusting the light emitting device along the first direction. Such an optical transmission system does not require the optical lens which has been conventionally used, and therefore, it is advantageous in realizing the miniaturization and reducing the number of parts.
In the above manufacturing method, preferably, the light emitting device has a plurality of light emitting units integrated with each other, and the plurality of light emitting units are disposed in the notch formed in the board.
In the above manufacturing method, preferably, the light emitting device has a plurality of light emitting units separated from each other; the board has a plurality of the notches; and the plurality of light emitting units are disposed in the notches.